Biosafety cabinets utilize filtration systems for filtering substances from an air flow through a work area thereof. The air flow is generated to maintain a negative pressure relative to the environment external to the biosafety cabinet, which prevents contaminants contained within the work area from being released or exposed to a user during operation. Oftentimes, contaminants that are captured on the surface of the filters of a biosafety cabinet filtration system are extremely hazardous and must be safely secured to ensure personnel and environmental protection. The working filtration surface (e.g., the filter face) of a filter contains the highest amount of such hazardous material, and thus creates the highest risk to the user or maintenance worker.
Filters in a biosafety cabinet must be periodically changed. The frequency of the change will vary by type of biosafety cabinet, the type of contaminants being filtered, the frequency of use, and the environment within the biosafety cabinet, among other factors. In order to protect the maintenance worker and the external environment, the filters must be sealed prior to being removed from the cabinet. This is commonly achieved by turning off the biosafety cabinet, placing the filter in one or more plastic bags, sealing the bags, and transporting for final destruction and/or disposal. More specifically, this replacement methodology requires shutdown of the biosafety cabinet supply fan to avoid issues with pressurization or depressurization of the plastic hag while being placed over the filter. In general, the external cabinet exhaust system must remain on, since shutting down both the supply fan and external cabinet exhaust system can compromise the ability to contain harmful chemical substances within the biosafety cabinet.
However, such known replacement systems are associated with numerous drawbacks. As just one example, they often require large, pre-installed equipment that holds both the filter and the bag in place. This adds to the overall costs and manufacturing expenses of the biosafety cabinet.
Still other known systems attempt to achieve safe removal by placing the filters at positions away from the work area, which often cannot be reached by a user or maintenance worker without use of a ladder. Such systems only offer limited visibility and mobility to the user or maintenance worker, who must perform the removal process on a ladder in full safety gear. Accordingly, such known systems may endanger the user or maintenance worker and create additional risks to the external environment. Dropping a contaminated filter from ladder height can allow the contaminant to spread (e.g., by diffusion) not only over an entire floor but also throughout an entire building, depending on the particular substance.
Accordingly, known systems demonstrate multiple shortcomings to the provision of a safe, convenient, and cost-effective way to remove and replace filters in a biosafety cabinet.